Capturing 24PA, DVCPRO via SDI, Blackmagic HD, FCP 5

[Glenn Chan]

1- If you finish on a 60i master, then you may be able to work with the footage as if it were 60i (just watch for timecode issues if you need to re-capture).

2- If you want a 24p master, then it’s easier if you capture via firewire. An advantage of a 24p master would be if you were making a DVD- 24p saves space (24fps progressive instead of 30fps interlaced; roughly 25% space saved, ignoring the interaction of interlaced/progressive with the encoder). If a 24p master is not a big deal, then you may just want to work in 60i. Sometimes this may be better, if the broadcaster wants the show packaged as a 60i master with very specific times (down to the frame).

Firewire carries the pulldown flags, which lets FCP know where the 2:3:3:2 cadence starts. Without these flags (i.e. when capturing over SDI and telling it to remove advanced pulldown), FCP will blindly guess the cadence and get it wrong (1 in 5 chance of guessing the cadence correctly). So instead of doing that, capture in 60i. You should be able to use Cinema Tools and manually guess the right cadence. Cinema Tools should take the 60i files and convert them to 24p files.

2b- Why not just capture firewire if you can?

3- If they are onlining 24pA footage elsewhere, you really need to pay attention. Some online systems (i.e. Mistika) can’t remove advanced pulldown. So either work with the footage as it were 60i footage, or make FCP remove the advanced pulldown *and* output something the online system will accept it.

[Viktor David]

Hi Glen, Our dvcprohd machine has only SDI or HDSDI out and no firewire. We are using blackmagic card to insure highest uncompressed quality and realtime effects. Any information for proper blackmagic capture and sequence settings for 24PA (not 24P) for digitizing via SDI would be greatly appreciated.

Thanks,

Vic

[Glenn Chan]

The following article might have useful information for you.
https://www.kenstone.net/fcp_homepage/pana_24p__cinetools.html

As you capture, make sure you check what the pulldown sequence is on the tape. See the article above.

So you’re basically:
A- capturing using a normal 60i 525/29.97fps preset / easy setup.
B- Removing advanced pulldown via Cinema Tools, which makes a bunch of 24p quicktimes.
C- Bring those quicktimes into a 24p FCP project (well 23.98p to be exact).

Or…
2- Ask the client if they want to edit in 60i. The 24pA footage is very similar to 60i footage and can be edited as such. If you need to get work done, this may be the way to do it.

3- Getting a deck with firewire out may make the capture process less painful. The quality should be the same if you can avoid re-compressing to DVCPRO50. If you are mastering to DVCPRO50, firewire capture would actually be slightly better (since its copying the data around, and you don’t incur any generation loss). The quality difference in any case may be neglible.

4- AFAIK, FCP can’t capture and accurately remove the advanced pulldown. There is a method of capture where FCP can capture and remove advanced pulldown at the same time. This will generate 24p uncompressed files. The problem however is that the advanced pulldown flags are not transmitted over SDI. So FCP can’t correctly guess where the cadence starts. When it guesses incorrectly, it will discard the wrong frame(s) and the resulting 24p file will have motion artifacts.

[Viktor David]

Hey Glen,
Are you familiar with blackmagic settings? Blackmagic has dozens of various capture and sequence presets. Many of them are 23.98 and 29.97 progressive. Some claim, blackmagic figured out the way for proper 24p Mode Advance (2:3:3:2 pulldown).

Getting a different dvcproHD deck with firewire is not an option at the moment.

Thanks in advance,

Vic

[Glenn Chan]

Can the deck actually remove the advanced pulldown for you? That way, it can spit out a 23.98fps signal and that won’t have any pulldown in it. So you could work with that. Just a guess here.

The AJ-HD1700 seems capable of that.
https://www.vtpcorp.com/htm/camcorderhdvtr.htm

Some claim, blackmagic figured out the way for proper 24p Mode Advance (2:3:3:2 pulldown).
I have no idea. I don’t believe it’s possible unless you can assume that the pulldown always starts/stops on a 0 or 5. But really, I wouldn’t know.

[Glenn Chan]

The AJ-HD1700 may not quite work, since you *must* upconvert the signal to get the deck to remove the pulldown.

23.98fps signals can’t be carried over standard definition SDI, although it can be carried over HD SDI. So I believe that is why the upconversion must occur.

However, it may defeat the point of capturing SDI to begin with, as going back down to SD may cause conversion artifacts/softening/whatever (or it may not, but sometimes downconverted HD signals can pickup noticeable aliasing).

2- As I see it, your best bets are:
A- Make a 60i master instead of a 24p master. For broadcast, they want a 60i master anyways usually.
B- Get a DVCPRO50 deck with firewire. Quality should be the same. This is not the same as capturing DVCPRO25 over firewire (where capturing over SDI will have chroma smoothing applied, and is sort of better quality).
C- Get an assistant editor / intern to capture the footage and tediously go through Cinema Tools and such.

[Viktor David]

Glenn,

thanks for your help. The deck we have is HD150 (which is really really great, except it doesn’t have firewire I/O), and I doubt we’ll be investing in new DVCPROHD machine in near future. I guess we’ll have to use cinema tools. BTW, thanks for the article, it was very useful. We are just starting with FCP, moving from Media 100, which is extremely stable and predictable, but lacking FCP features and not an industry standard.

Once again, thanks for your help, and if you hear anything new about blackmagic 2:3:3:2 setting please let me know.

Regards,

Vic